PROJECT SUMMARY/ABSTRACT Elderly patients with cancer have a higher risk of bony metastases than middle-aged patients (four times higher in men and three times higher in women). Approximately 50% of these cases of bony metastases involve the spine. Cancer patients are living longer as a result of new and aggressive treatments, but at sites of skeletal metastasis fractures occur in 17%-35% of affected bones after minimal trauma. Fractures due to metastatic disease in the spine vary from stable fractures with minimal pain and impairment to unstable fractures causing pain, major functional impairment, and neurologic deficits. Moreover, axial, skeletal metastases and the resultant fractures increase the risk for spinal instability, spinal cord compression, and neurological compromise. These complications have a devastating effect on quality of life, and, therefore prediction and prevention of fractures due to metastatic disease in the spine is critical. Clinicians currently make subjective assessments regarding a patient's fracture risk and response to treatment, which are now recognized to be inaccurate. To address this shortcoming, we have developed a methodology called Computed Tomography-based Rigidity Analysis (CTRA) for assessment of bone fracture risk. This method uses computed tomography (CT) images of the bone to calculate its structural rigidity, as a mechanical assay representing changes in bone tissue material and geometry induced by different factors such as age, trauma, or the neoplastic process. CTRA has been shown to provide estimates of bone load capacity and predict pathologic fractures in 20 ex-vivo, pre-clinical, and clinical studies. BioSensics is currently working on the development and commercialization of CTRA software for appendicular skeleton. This effort includes software design, as well as development of reimbursement strategies for CTRA, which is critical for large scale clinical usage of the technology and successful commercialization. In this Direct Phase II SBIR application, BioSensics, in collaboration with Beth Israel Deaconess Medical Center and Mayo Clinic, proposes to significantly expand the commercialization potential of CTRA by expanding its application to the axial skeleton. The aims of this project are to 1) Develop an age-, race- and gender-based normative structural rigidity database for the axial skeleton, 2) Develop fracture threshold values for CTRA analysis, 3) Develop auto-segmentation and material properties assignment algorithms, and 4) Develop and validate the CTRA software solution for axial skeleton. Software development will follow design controls in accordance with 21 CFR 820.30 and include life cycle processes required for the safe maintenance of the CTRA software based on International Standard IEC 62304 for medical device software.